The present invention relates to brake controllers for electrical braking systems on a towed vehicle. More particularly, the present invention relates to a unique control housing assembly for use with the electrical braking system.
Towed vehicles, such as recreational and utility trailers which are designed to be towed by automobiles and light-duty trucks, are commonly provided with electric brakes. The electric brakes generally include a pair of brake shoes which, when actuated, frictionally engage a brake drum. An electromagnet is mounted on one end of a lever to activate the brake shoes. When an electric current is supplied to the electromagnet, the electromagnet is drawn against the rotating drum which pivots the lever to actuate the brakes. Typically, the braking force produced by the brake shoes is proportional to the electric current applied to the electromagnet. This electric current can be relatively large. For example, the electric brakes on a two-wheeled trailer can draw six amperes of current when actuated and the electric brakes on a four-wheel transfer can draw twelve amperes of current.
Automobile industry standards require that electrically actuated vehicle brakes be driven against the ground potential of the vehicle power supply. Accordingly, one pole of each of the towed vehicle brake electromagnets is electrically connected to the towed vehicle ground and the towed vehicle ground is electrically grounded to the towing vehicle ground. The other pole of each of the brake electromagnets is electrically connected through an electric brake controller to the towing vehicle power supply.
Various electric brake controllers for towed vehicle electric brakes are known in the art. For example, a variable resistor, such as a rheostat, can be connected between the towing vehicle power supply and the brake electromagnets. The towing vehicle operator manually adjusts the variable resistor setting to vary the amount of current supplied to the brake electromagnets and thereby control the amount of braking force developed by the towed vehicle brakes.
Also known in the art are more sophisticated electric brake controllers which include electronics to automatically supply current to the brake electromagnets when the towing vehicle brakes are applied. Such electronic brake controllers typically include a sensing unit which generates a brake control signal corresponding to the desired braking effort. For example, the sensing unit can include a pendulum which is displaced from a rest position when the towing vehicle decelerates and an electronic circuit which generates a brake control signal which is proportional to the pendulum displacement. Alternatively, the hydraulic pressure in the towing vehicle""s braking system or the pressure applied by the driver""s foot to the towing vehicle""s brake can be sensed to generate the brake control signal.
Other brake controllers are designed to generate an output signal for actuating the electric wheel brakes of the towed vehicle when a signal is received which indicates the towing vehicle""s brakes are being applied. The strength of the output signal and thus the amount of braking is selected by the operator of the vehicle. Typically, the strength is incrementally adjustable between a plurality of individual strength settings. A display of some type is utilized to indicate the strength of braking that has been selected. This type of a brake controller may also include a device for producing a manual brake control signal which overrides the automatically generated brake control signal. The device is actuated by the operator to generate the braking signal when the operator wants the towed vehicle electric brakes applied when the towing vehicle""s brakes are not applied.
While these prior art brake controllers have performed adequately in the prior art, the continued development of these controllers has been directed to simplification and lowering of the costs for these controllers.
The present invention provides the art with a controller that utilizes computer mouse technology to determine the level of braking to be applied. By utilization of computer mouse technology, the controller of the present invention utilizes digital control rather than the potentiometer systems of the prior art. By using digital control rather than the prior art potentiometer systems, the controller of the present invention can be programmed to apply one-hundred percent of trailer braking regardless of where the maximum set percentage of braking is set.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.